The invention relates to an aiming device for improving the aiming or firing on movable targets, particularly airborne targets, by means of which the so-called apparent direction of flight, defined by the target course, and the lead angle or the components thereof (by azimuth angle as well as the so-called super elevation), are determined.
Such a device is particularly suitable for use in connection with antiaircraft weapons and may be mounted directly on guns, as a so-called lead calculator, and may also be used for central firing control equipment.
When firing on movable targets, the weapon must be pointed ahead of the target, that is, set to the so-called lead point, which is located ahead of the target on the target course on which the target will be located after lapse of the projectile flight time, provided the target has not changed its path.
In addition, the gun barrel must be raised by the super elevation angle measured with respect to the sighting beam, so that the projectile will fly to the predetermined lead point.
A device is known, in which the so-called flight plane defined by the assumed straight line of this target course and the equipment site is determined by two sighting beams originating from the position of the equipment tracking each momentary position of the target, whereby mechanical elements associated with the sight beams for the purpose of fixing the setting plane in the equipment according to the flight plane may be adjusted by directional motions. Such a device has been described in the German Pat. Specifications No. 953047. Under the present state of the art, devices for determining the lead point in the flight plane, in which the lead angle is determined, at least partially, by mechanical reproductions in the lead triangle are known. Such a device is described in the Swiss Pat. Specifications No. 369383.
However, these devices exhibit various shortcomings. For instance, the apparent direction of flight can be determined precisely only if the target changes from the first sighting beam by an angle of a minimum value, whereagainst this device fails, due to mechanical reasons, in "near approaches". Additionally, the plane of observation in this device must initially be coarsely adjusted to the projected motion of the target, thus causing a certain loss of time. The prior art device for determining the lead angle performs theoretically exact calculations only for horizontal target paths and not for inclined target paths. For mechanical reasons it fails when an elevation angle is small.
Pursuant to the invention, the aiming device for improving the aiming or firing on movable targets, especially flying targets, is characterized by the combination with a sight device being capable of sensing and measuring succeeding positions of a target in space by azimuth and elevation angle of a computer having a memory unit for storing data obtained from the measuring of the azimuth and elevation angle of at least one position of a target in space picked up by means of the sight device (first determining beam), and for storing a program for manipulating trigonometric and spherical relations relating to straight flight paths, as well as the interrelationships of the ballistic characteristics of the ammunition used, (firing angle and projectile flight time and, respectively, average projectile velocity), of a device for the input of an estimated or otherwise determined target distance into the computer, of a device for the input of an estimated or otherwise determined target velocity into the computer, all of it arranged in such a cooperation that the computer determines the apparent direction of the reference plane, defined by the two beams by means of data obtained by the first determining beam of the picked-up target, and by data of the momentary direction of the sighting beam (second determining beam) obtained from the measuring device, whereby this direction merges with the desired apparent flight direction of the target, if it is sighted at any given point of this apparent flight direction. In addition, the computer determines the lead angle or its components with respect to azimuth and elevation in the flight plane, as well as the firing angle.
The computations are thus based on two sighting beams from the aiming device whereby the specific values (azimuth and elevation angle) are constant in the first determining beam and variable with the second determining beam depending on the directional motion of the aiming device. It is important to note that those two determining beams define an imaginary plane which may be characterized as a setting plane, which the sensor, i.e., the eye perceives as a straight line of setting and which rotates about the point fixed by the first sighting beam when the sighting device is moved, i.e., this point constitutes the conversion point of all straight setting lines. The setting plane merges with the flight plane as soon as the target is sighted with an arbitrary point of the straight reference line, thus determining the apparent flight-direction.
The sensor, i.e., the starting point of the target sensing beams or sighting beams, is usually the eye of the curious observer, but purely technical devices, such as radar, may also be used for detection.